Infrared matrix spectra of the N2O ···O2 complex in solid nitrogen. The N2O ··· O2+O thermal diffusion limited reaction

The vibrational spectrum of N2O diluted in a nitrogen matrix is compared to the spectrum of N2O produced after the photolysis of ozone diluted in solid nitrogen. The small shift observed between the two spectra is due to the formation of a 1−1 complex between nitrous oxide and molecular oxygen. Upon increasing the temperature, the complex formed after the photolysis of ozone in nitrogen reacts with an oxygen atom leading to O3 and N2O. Analysis of the results brings new information on oxygen atom diffusion in cryogenic solids. As predicted by theoretical investigations, the long-range diffusion of atomic oxygen in a nearly perfect matrix is negligible between 20 and 30 K. However, a fast motion of O(3P) at short range, independent of the matrix morphology, is experimentally suggested between 15 and 20 K.